The present invention pertains to that type of sign having several interleaved panels which move individually to display the panels and the indicia thereon in sequence.
The prior art includes such signs which have been referred to as "slat signs" or "interleaved signs" wherein a panel provides a display by moving into view and, conversely, by retracting out of view to reveal an underlying panel.
In the past such signs relied on complicated drive mechanisms utilizing arrays of cams, levers, linkages, etc., to shift a panel into view and later retract same from view. The prior art mechanisms severely curtail the number of panels usable in a sign and accordingly restrict the sign's commercial usefulness. For example, the sign disclosed in U.S. Pat. No. 3,430,371 embodies three panels to show only three messages or visual displays to a viewer located forwardly of the sign. Additional displays or messages may be carried on the back side of the panels which, of course, are not visible to the forwardly located viewer.
U.S. Pat. Nos. 2,141,398; 2,829,456; 3,013,352; 3,080,668; 3,421,240; 4,102,608 and 4,164,086 additionally provide sliding display panels wherein manual or motorized movement of a panel repositions a panel with interleaved strips into view. Commonly, such panels are comprised of horizontal or vertical strips with the strips of a panel joined by common marginal areas to which motion is imparted by the actuating mechanism of the sign to move the strips of one panel relative to the strips of the other panels.
In addition to the drawback of only a severely limited number of displays being possible with the prior art signs, other drawbacks are high cost of manufacture and maintenance incurred by the complex actuating mechanisms. Further, the noise generated by various mechanical components render such signs usable only in "noisy" environments. The unsatisfactory relationship of overall sign size to display area is still another disadvantage to known sign construction.